United States

We analyze models of decaying dark matter, searching for shifts in $H_0$ and $\sigma_8$ to resolve the tensions between linear and astrophysical measurements. While previous searches have focused on dark matter with lifetimes on the order of the current Hubble time, we instead consider dark matter that decays between the time of last scattering and the era of large scale structure. We find that while decaying dark matter pushes parameter likelihoods in the right direction to resolve the Hubble Tension, the bounds ($\Omega$ = 0 to 10^-2 for lifetimes a tenth of the Hubble Time) on decaying dark matter are too strong to resolve the tension completely, a conclusion unchanged even when spatial curvature is allowed to vary. In addition, these bounds can be used to constrain theoretical models such as coupled axions from string compactifications.

AAPT WM 21

The Effects of Decaying Dark Matter on The Hubble Constant

cosmology

dark matter

hubble tension

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Probing Understanding of Buoyant Force and Volume of Fluid Displaced

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QuarkNet LHC Data Workshops

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QuarkNet High School Cosmic Ray Projects

Positive attitude is&nbsp;important in learning physics. Students and teachers can have fun together inside and outside classrooms.&nbsp;

Improving Positive Attitude in Learning Physics

This presentation will provide an overview of presentations that will be available to those attending for use with their classes.The presentations are intended for use with students in grades 6-9, 10-12, and introductory college classes. Climate science challenges are presented in terms of entropy changes that occur due to procuring and burning fossil fuels to produce electricity. Infromation about the Climate Reality Project is also included.

A Thermodynamic approach to Climate Science

What is science?&nbsp; What are the psychological, economic, and political factors that shape people's decisions about truth or fact?&nbsp; Do truth, facts, or opinions guide science and technology policies?&nbsp; These are the questions we address in a one credit seminar for first-year students.&nbsp; The seminars were developed as part of Spelman College’s Big Questions Colloquia, and they cover many different areas. &nbsp;In this seminar, students learn about how people reason and what science is. Eventually, students build skills to help them critique policies and differentiate between science and pseudoscience.&nbsp; We explore controversial topics like big tobacco, and look at some conspiracy theories, such as the Apollo hoax. From the seminar, students gain experience critiquing, evaluating, and thinking about science and related policies.&nbsp; I will present my experiences with developing the seminar, and some strategies for building an interdisciplinary approach to communicating about science.

An Interdisciplinary Seminar on Knowledge, Science, and Policy

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Studying the Past to Understand the Present

The air we breathe is constantly changing. The dynamic nature of outdoor and indoor air makes it interesting to measure. There are many natural opportunities in an intro electromagnetism course for students and professors to observe how quantities like carbon dioxide, methane, and particulate matter change over time. We will look at a few sensors that measure various gases and particles in the air. Then we will discuss ideas for integrating them into the intro physics classroom. Understanding what influences the air gives students an interest in the atmosphere around them and offers them a chance to change it with their actions.

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The Effects of Decaying Dark Matter on The Hubble Constant

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